As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
START CONTACTOR STUCK IN CLOSED POSITION. TURNED MASTER ON AND STARTER MOTOR WOULD ENGAGE, HAVE TO TURN MASTER OFF TO STOP STARTER. THIS CONTACTOR WAS CHANGED 8 MONTHS AGO FOR SAME PROBLEM. HAVE HAD SAME PROBLEM ON OTHER MAKES OF ACFT IN THE PAST. SEEMS TO COINCIDE WITH THE USE OF HIGH TORQUE STARTERS. VERY DANGEROUS.